Before the Experiment...
Who?
Kristy from Group 17
What?
To test whether the amount the sugar added to the egg whites affects the height of the soufflé.
The research hypothesis is that when a greater amount of sugar is added to the egg whites, the souffle would rise taller.
Ingredients include butter, caster sugar, bread flour, milk, vanilla extract and eggs.
Tools include whisk, electric mixer, bowls, electronic scale, plastic spatula, spoons, oven, butter brush, markers and bamboo sticks.
Where?
Kristy's home.
I have all the ingredients except egg at home so I bought some eggs from the supermarket.
I have all the tools at home.
When?
In four experiments, add a different amount of sugar while whisking the egg whites.
In each experiment, make sure the time of beating the egg is the same.
The height of the soufflé will be measured immediately after removing out from the oven.
Why?
To find out if the amount of sugar added to the egg whites affects the height of the souffle.
Egg whites contain a complex network of proteins that serve as emulsifiers.
Sugar aid the egg whites in forming tight protein bonds (SBS). Sugar also help stabilise the structure of egg whites as it dissolves the protein on the surface of the air bubbles (Corriher; Food Crumbles). Sugar also help increasing the viscosity of the liquid egg whites that makes it more difficult for the air bubbles to merge together and escape (Food Crumbles), thus slowing down the rate at which foams dissipate. When there are more sugar inside the whites, the more water will be drawn out and evaporated, resulting in a drier and stiffer egg white peaks (Corriher). If there is not enough sugar, the soufflé may not hold its shape and may collapse quickly.
How?
Carry out four experiments by making soufflé in the same method but with a different amount of sugar added to the egg whites in each experiment (Reduce 5g per experiment: 25g, 20g, 15g, 10g). In the experiment with the amount of sugar recommended by the recipe (20g of sugar added to the egg whites), the time required to beat the egg whites until peaks form will be measured. The other three experiments will follow this amount of time used to beat the egg whites. The height of the soufflé will be measured immediately after removing out from the oven to get the most accurate result as soufflé can collapse very quickly. The height of the souffle will be measured by inserting a bamboo stick into the highest point of the soufflé, then a marker will be used to mark its height onto the stick. The marked height on the bamboo sticks with be measured with a ruler. Finally, the results in the experiments will be compared.
Independent Variable
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Dependent Variables
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Controlled Variables
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Amount of sugar added to the egg whites (Reduce 5g per experiment: 25g, 20g, 15g, 10g)
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The height of the soufflé
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Amount of all ingredients, source of all ingredients, beating speed of egg yolk and egg white, beating time of egg yolk and egg white, size of ramekins, amount of batter poured into ramekins, baking time and baking temperature
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First Experiment
I decided to change the recipe and started all over again because the recipe that I used earlier uses only one egg. The soufflé made are very short which results in a small difference between the experiment results when I change the independent variable. The amount of batter made is also not enough to fill up the ramekins. I think the reason is that there are not enough eggs in the recipe I used earlier. The following is the new recipe but when I do the experiment on my own, I can only fill up 1-2 ramekins:
Recipe:
Vanilla Souffle (For four 3-inch ramekins)
Ingredients:
5g butter (for brushing ramekins)
20g sugar (for coating ramekins)
2 egg yolks
15g sugar (for egg yolks)
12g cake flour
17g Butter
82g Milk
2 egg whites
20g sugar (for egg whites)
1 tsp vanilla extract
Steps:
1. Preheat the oven at 190°C.
2. With a pastry brush, grease the ramekins with softened butter in upward strokes (this will help the soufflé rise evenly). Then coat the ramekins in caster sugar. Keep the prepared ramekins in the fridge to set until ready to use.
3. Mix the egg yolks with sugar until even and sift the cake flour into the mixture. Mix well until smooth.
4. Put butter, milk and vanilla extract into a saucepan and boil them over medium heat until melt. Remove from heat.
5. Slowly pour (4) into (3) and mix well.
6. Pour the batter back into the saucepan. Whisk it over medium heat until thickens.
7. Pour the batter into another bowl and let cool until lukewarm.
8. Whisk the egg whites and add sugar for a few times. Whisk until the egg whites form peaks.
9. Scrape out 1/3 egg white with a plastic spatula and combine with the batter. Then softly fold the egg white into the batter.
10. Pour the mixture into four ramekins.
11. Bake in the oven at 190°C for 10 minutes and at 180°C for another 5 minutes.
12. Remove from the oven and serve immediately.
Results
Final product & remarks
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Did not take a picture of the batter. Below is the picture before folding with egg whites.
The amount of batter is enough to fill up two ramekins.
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The batter is whiter in color, smooth, light and airy.
The amount of batter is enough to fill up two ramekins.
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The batter is quite smooth but there are large bubbles.
The amount of batter can only fill up one ramekin.
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10g
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The batter shows a lumpy texture that the egg whites could not mix well with the egg yolk batter.
The amount of batter can only fill up one ramekin.
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Visualization of the data
Trend/ Pattern/ Correlation between IV and DV
When 20g of sugar is added to the egg whites, the souffle is the tallest with a height of 7.9 cm. When we look at the result of 20g, 15g and 10g of sugar are added to the egg whites, there is an increasing trend of height from 10g to 20g. This proves when more sugar is added to the egg whites, the souffle will be taller. However, when 25g of sugar is added to the egg whites, the souffle is 0.9cm shorter than the souffle made with 20g of sugar.
Analysis
When there is more sugar in the egg whites, it is easier for the egg whites to form peaks and bubbles are finer and smaller. However, when there is too much sugar (25g) in the egg whites, strong peaks cannot be formed.
In the experiments that 15g and 10g of sugar are added to the egg whites, the meringue
have large bubbles without much air in it. This resulted in a smaller amount of batter when compared with the experiments done with 20g and 25g of sugar. The experiments done with 20g and 25g of sugar have more air inside the batter so even with variables are controlled, the amount of the batter doubled that they can fill up two ramekins.
In the experiment with 10g of sugar in the egg whites, the batter has a lumpy texture. This is because the egg white is very watery while the egg yolk batter has a thicker density that makes it more difficult to fold together smoothly.
Minimizing errors for the next experiment and shortcomings
Before doing the experiments, I did a trial and I used a ruler to measure the height of the souffle, which includes the height of the ramekin. I found this method inaccurate as there could be errors in the measurement. That is why in these experiments, I used a bamboo stick to insert into the highest point of the souffle and mark its height with a marker.
However, I need to make sure that the bamboo stick is vertically straight when I mark the height. Otherwise, the results can be inaccurate.
However, I need to make sure that the bamboo stick is vertically straight when I mark the height. Otherwise, the results can be inaccurate.
Also, the egg whites and egg yolk can have different weight so it is better to weigh them to ensure their amount are kept controlled.
For the experiments of 25g and 20g of sugar, I made two souffle but I only took the result of the higher ramekin. For the experiments with 15g and 10g of sugar, I only made one souffle as there is not enough batter. This makes it more difficult to compare the result.
For the experiments of 25g and 20g of sugar, I made two souffle but I only took the result of the higher ramekin. For the experiments with 15g and 10g of sugar, I only made one souffle as there is not enough batter. This makes it more difficult to compare the result.
Reference
Cooking Tree. (2018). Retrieved from https://www.youtube.com/watch?v=IJYvg1NhzMQ&t=342s.
Corriher, Shirley. “How Fragile Egg-White Foams are Transformed into Firm, Airy Meringues’ by Fine Cooking https://www.finecooking.com/article/how-fragile-egg-white-foams-are-transformed-into-firm-airy-meringues
Food Crumbles. “The science of meringue: egg whites and sugar” https://foodcrumbles.com/a-blog-on-meringue-a-literature-study/
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